The use of polymer compositions in surgical procedures is now widely recognized, particularly those compositions manufactured with synthetic polymers. In contrast to many naturally derived compositions, synthetic polymer compositions can be formulated to exhibit predetermined physical characteristics, such as gel strength, as well as biological characteristics, such as biodegradability.
Several two-part co-polymer systems have been described that can be administered as liquids, or solutions, but which subsequently form gels at the site of administration. See, for example, U.S. Pat. Nos. 5,874,500 (Rhee et al., issued Feb. 23, 1999), 6,051,648 (Rhee et al., issued Apr. 18, 2000), 6,312,725 (Wallace et al., issued Nov. 6, 2001), 6,458,889 (Trollsas et al., issued Oct. 1, 2002), 6,495,127 (Wallace et al., issued Dec. 17, 2002), 6,624,245 (Wallace et al., issued Sep. 23, 2003), 7,176,256 (Rhee et al., issued Feb. 13, 2007), and U.S. Patent Application Publication No. 2005/0281883 A1 (Daniloff et al.), all of which are hereby incorporated by reference herein in their entirety, including any drawings. Such in situ gel-forming compositions are convenient to use since they can be administered as liquids from a variety of different devices, and are adaptable for administration to any site, since they are not preformed.